Raspberry PI is a wonderful system and OpenCV is an outstanding library for computer vision. Here is our how to install and configure OpenCV 3.2.0 for Python/C++ on a Raspberry PI 2 with Raspbian Jessie. On the Net there are many references on this subject, most of them have some missed point or reference to old versions.
OpenCV means Open Source Computer Vision Library. It is software library that implement many popular Image Processing, Computer Vision and machine learning algorithms.